import NNG.Levels.Power.Level_4 Game "NNG" World "Power" Level 5 Title "pow_add" open MyNat Statement MyNat.pow_add "For all naturals $a$, $m$, $n$, we have $a^{m + n} = a ^ m a ^ n$." (a m n : ℕ) : a ^ (m + n) = a ^ m * a ^ n := by induction n with t ht · rw [add_zero, pow_zero, mul_one] rfl · rw [add_succ, pow_succ, pow_succ, ht, mul_assoc] rfl LemmaTab "Pow"